Add a script to count places we skip code on site isolated frames

https://bugs.webkit.org/show_bug.cgi?id=265558
rdar://118958958

Reviewed by Alex Christensen.

This probably isn't comprehensive, and some of these may not need fixing, but it provides a rough estimate
we can use to track our progress.

Similar to `count-handwritten-cocoa-decoders`.

* Tools/Scripts/count-skipped-out-of-process-frames: Added.

Canonical link: https://commits.webkit.org/271316@main

Tools/Scripts/count-skipped-out-of-process-frames

@@ -0,0 +1,23 @@
+#!/bin/sh
+#
+# This script scans Source/WebCore and Source/WebKit/WebProcess for places where we are likely skipping code on out-of-process frames and provides a count.
+#
+
+count_occurrences() {
+    local pattern=$1
+    local flag=$2
+    grep "$flag" "$pattern" "$(dirname "$0")/../../Source/WebCore" "$(dirname "$0")/../../Source/WebKit/WebProcess" | wc -l | xargs
+}
+
+downcastLocalFrame=$(count_occurrences "[dD]owncast<\(WebCore::\)\?LocalFrame>" "-r")
+downcastLocalFrameView=$(count_occurrences "[dD]owncast<\(WebCore::\)\?LocalFrameView>" "-r")
+topDocument=$(count_occurrences "topDocument()" "-r")
+parentDocument=$(count_occurrences "parentDocument()" "-r")
+
+echo "Downcast LocalFrame remaining: $downcastLocalFrame"
+echo "Downcast LocalFrameView remaining: $downcastLocalFrameView"
+echo "topDocument() remaining: $topDocument"
+echo "parentDocument() remaining: $parentDocument"
+
+sum=$((downcastLocalFrame + downcastLocalFrameView + topDocument + parentDocument))
+echo "Total skipped out-of-process frames remaining: $sum"